Margins that start at fragmentainer boundaries should be collapsed away.

third_party/WebKit/Source/core/layout/LayoutBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 1869 matching lines @@
                                      includeBlockOverflows);
     }
   }
 }
 
 LayoutBox* LayoutBlock::createAnonymousBoxWithSameTypeAs(
     const LayoutObject* parent) const {
   return createAnonymousWithParentAndDisplay(parent, style()->display());
 }
 
-LayoutUnit LayoutBlock::nextPageLogicalTop(LayoutUnit logicalOffset) const {
-  LayoutUnit pageLogicalHeight = pageLogicalHeightForOffset(logicalOffset);
-  if (!pageLogicalHeight)
-    return logicalOffset;
-
-  return logicalOffset + pageRemainingLogicalHeightForOffset(
-                             logicalOffset, AssociateWithLatterPage);
-}
-
 void LayoutBlock::paginatedContentWasLaidOut(
     LayoutUnit logicalBottomOffsetAfterPagination) {
   if (LayoutFlowThread* flowThread = flowThreadContainingBlock())
     flowThread->contentWasLaidOut(offsetFromLogicalTopOfFirstPage() +
                                   logicalBottomOffsetAfterPagination);
 }
 
 LayoutUnit LayoutBlock::collapsedMarginBeforeForChild(
     const LayoutBox& child) const {
   // If the child has the same directionality as we do, then we can just return
@@ skipping 299 matching lines @@
   }
 
   return availableHeight;
 }
 
 bool LayoutBlock::hasDefiniteLogicalHeight() const {
   return availableLogicalHeightForPercentageComputation() != LayoutUnit(-1);
 }
 
 }  // namespace blink